In situ effect of strontium toothpaste on artificially decalcified human enamel.

The aim of this study was to measure the strontium levels in surface and subsurface artificially decalcified enamel exposed in situ to a strontium-supplemented toothpaste. Twenty healthy premolar teeth extracted for orthodontic reasons were cut into blocks and demineralized. The samples were cemented to the teeth of six volunteers who brushed with a hydroxyapatite (HAP) and HAP strontium-supplemented toothpaste for 3 and 6 mo. The strontium content in the enamel surface and in the lateral wall of the enamel samples was evaluated using energy-dispersive spectrometry microanalysis. After 3 mo, the strontium content in the enamel surface increased significantly compared to baseline values. On the lateral enamel surfaces, the strontium level was the same in all of the layers after 6 mo and was higher than the level observed after 3 mo. Regular toothbrushing with a strontium-supplemented toothpaste has been found to increase the strontium content in the exposed enamel, which can be an advantage in the prevention of cariogenesis.